Very dark screen on Toshiba M115

July 4, 2012 at 06:31:10
Specs: Windows XP
Booting up the laptop, the on board screen is very dark. The computer is running perfectly as I've plugged in an external monitor and everything is fine. It's just the on board screen, I can see the contents, just. Does this sound like the screen or the "inverter" problem? I'm presuming it's the backlight but not sure if thats built into the screen or does the inverter create the light?

See More: Very dark screen on Toshiba M115

Report •

July 4, 2012 at 06:39:47
Iv seen this issue many times on Dell laptops, never on a Toshiba, but on every occassion changing the inverter board solved the issue. you can pick up inverters on ebay for next to nothing and they are pretty straight forward to change.

if you take off the screen bezel you should be able to access the board at the bottom without too much fidling around.

Report •

July 4, 2012 at 15:19:08
Your problem is VERY COMMON.

Try connecting an external monitor to your laptop
In most cases there's nothing wrong with the video adapter and the display will be fine on that

Laptop no video (or video problems), and battery, AC adapter, power jack T shooting.

See response 1:

DO NOT plug in or unplug a monitor's video cable into / from a video port while the computer is running. Doing so can damage the monitor's circuits and/or the video adapter's circuits.

Some laptops will display on an external monitor without you having to do anything.

If you get no video on an external monitor, some laptops have a key combo that you must press to toggle the display to external video only / built in display video only / sometimes both - see the Owner's or User's manual for the model (e.g. press both Fn and Fx ; x is a number).

"I'm presuming it's the backlight but not sure if thats built into the screen or does the inverter create the light?"

The baclight is a CCFL - Cold Cathode Florescent Lamp - the voltage inverter supplies high voltage to it.
The backlight produces progressively less light as time goes on, and burns out eventually, just like any other florescent bulb.

The backlight provides the white light source behind the the liquid crystal pixels.
The liquid crystal pixels let the white light come through, or they color it, or they block it completely.

If there are ANY graphics on the screen, the backlight is ON, therefore, screen savers that display anything at all do NOT lengthen the useful life of the backlight.

It's probably a lot more likely the backlight is in the final stages of failure than there's anything wrong with the voltage inverter.

Report •
Related Solutions

Ask Question